1. Technical Field
The present disclosure generally relates to robotic technologies, and particularly, to an robot arm assembly.
2. Description of Related Art
A commonly used industrial robot includes a fixed base, a frame pivotally connected thereto about a first rotation axis, a lower arm, one end of which is pivotally connected to the frame about a second rotation axis, and an upper arm, one end of which is pivotally connected to the other end of the lower arm about a third rotation axis. An end effector, such as a welding device, a gripper or a cutting tool, is mounted at a distal end of the upper arm. Generally six axes are utilized to achieve maximum amount of movements of the end effector.
In robots of this kind, each arm rotates around a rotation axis driven by a driving unit. Typically, the driving unit includes a motor mounted on the lower arm and a speed reducer coupled to the motor to transmit the movement of the motor to the upper arm. The speed reducer may be a high gear ratio gear, such as a harmonic gear reducer, a rotary vector reducer, or a planetary reducer. The motor and the speed reducer are arranged along the rotation axis of the arm, rendering the range along the rotation axis relatively large. In a six-axis industrial robot, the fifth arm is rotatably connected to the sixth arm and may be perpendicular thereto. The fifth and sixth arms are respectively driven by two driving units arranged adjacent to each other, such that the combined fifth and sixth arms are relatively large. As a result, the industrial robot needs considerable amount of space to operate freely and safely.
Therefore, there is room for improvement within the art.